spandsp  0.0.6
async.h
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1 /*
2  * SpanDSP - a series of DSP components for telephony
3  *
4  * async.h - Asynchronous serial bit stream encoding and decoding
5  *
6  * Written by Steve Underwood <steveu@coppice.org>
7  *
8  * Copyright (C) 2003 Steve Underwood
9  *
10  * All rights reserved.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU Lesser General Public License version 2.1,
14  * as published by the Free Software Foundation.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with this program; if not, write to the Free Software
23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24  */
25 
26 /*! \file */
27 
28 /*! \page async_page Asynchronous bit stream processing
29 \section async_page_sec_1 What does it do?
30 The asynchronous serial bit stream processing module provides
31 generation and decoding facilities for most asynchronous data
32 formats. It supports:
33  - 1 or 2 stop bits.
34  - Odd, even or no parity.
35  - 5, 6, 7, or 8 bit characters.
36  - V.14 rate adaption.
37 The input to this module is a bit stream. This means any symbol synchronisation
38 and decoding must occur before data is fed to this module.
39 
40 \section async_page_sec_2 The transmitter
41 ???.
42 
43 \section async_page_sec_3 The receiver
44 ???.
45 */
46 
47 #if !defined(_SPANDSP_ASYNC_H_)
48 #define _SPANDSP_ASYNC_H_
49 
50 /*! Special "bit" values for the bitstream put and get functions, and the signal status functions. */
51 enum
52 {
53  /*! \brief The carrier signal has dropped. */
55  /*! \brief The carrier signal is up. This merely indicates that carrier
56  energy has been seen. It is not an indication that the carrier is either
57  valid, or of the expected type. */
59  /*! \brief The modem is training. This is an early indication that the
60  signal seems to be of the right type. This may be needed in time critical
61  applications, like T.38, to forward an early indication of what is happening
62  on the wire. */
64  /*! \brief The modem has trained, and is ready for data exchange. */
66  /*! \brief The modem has failed to train. */
68  /*! \brief Packet framing (e.g. HDLC framing) is OK. */
70  /*! \brief The data stream has ended. */
72  /*! \brief An abort signal (e.g. an HDLC abort) has been received. */
74  /*! \brief A break signal (e.g. an async break) has been received. */
76  /*! \brief A modem has completed its task, and shut down. */
78  /*! \brief Regular octet report for things like HDLC to the MTP standards. */
80  /*! \brief Notification that a modem has detected signal quality degradation. */
82  /*! \brief Notification that a modem retrain has occurred. */
84  /*! \brief The link protocol (e.g. V.42) has connected. */
86  /*! \brief The link protocol (e.g. V.42) has disconnected. */
88  /*! \brief An error has occurred in the link protocol (e.g. V.42). */
90 };
91 
92 /*! Message put function for data pumps */
93 typedef void (*put_msg_func_t)(void *user_data, const uint8_t *msg, int len);
94 
95 /*! Message get function for data pumps */
96 typedef int (*get_msg_func_t)(void *user_data, uint8_t *msg, int max_len);
97 
98 /*! Byte put function for data pumps */
99 typedef void (*put_byte_func_t)(void *user_data, int byte);
100 
101 /*! Byte get function for data pumps */
102 typedef int (*get_byte_func_t)(void *user_data);
103 
104 /*! Bit put function for data pumps */
105 typedef void (*put_bit_func_t)(void *user_data, int bit);
106 
107 /*! Bit get function for data pumps */
108 typedef int (*get_bit_func_t)(void *user_data);
109 
110 #define modem_rx_status_func_t modem_status_func_t
111 #define modem_tx_status_func_t modem_status_func_t
112 
113 /*! Status change callback function for data pumps */
114 typedef void (*modem_status_func_t)(void *user_data, int status);
115 
116 /*!
117  Asynchronous data transmit descriptor. This defines the state of a single
118  working instance of a byte to asynchronous serial converter, for use
119  in FSK modems.
120 */
122 
123 /*!
124  Asynchronous data receive descriptor. This defines the state of a single
125  working instance of an asynchronous serial to byte converter, for use
126  in FSK modems.
127 */
129 
130 enum
131 {
132  /*! No parity bit should be used */
134  /*! An even parity bit will exist, after the data bits */
136  /*! An odd parity bit will exist, after the data bits */
138 };
139 
140 #if defined(__cplusplus)
141 extern "C"
142 {
143 #endif
144 
145 /*! Convert a signal status to a short text description.
146  \brief Convert a signal status to a short text description.
147  \param status The modem signal status.
148  \return A pointer to the description. */
149 SPAN_DECLARE(const char *) signal_status_to_str(int status);
150 
151 /*! Initialise an asynchronous data transmit context.
152  \brief Initialise an asynchronous data transmit context.
153  \param s The transmitter context.
154  \param data_bits The number of data bit.
155  \param parity_bits The type of parity.
156  \param stop_bits The number of stop bits.
157  \param use_v14 TRUE if V.14 rate adaption processing should be used.
158  \param get_byte The callback routine used to get the data to be transmitted.
159  \param user_data An opaque pointer.
160  \return A pointer to the initialised context, or NULL if there was a problem. */
162  int data_bits,
163  int parity_bits,
164  int stop_bits,
165  int use_v14,
166  get_byte_func_t get_byte,
167  void *user_data);
168 
169 SPAN_DECLARE(int) async_tx_release(async_tx_state_t *s);
170 
171 SPAN_DECLARE(int) async_tx_free(async_tx_state_t *s);
172 
173 /*! Get the next bit of a transmitted serial bit stream.
174  \brief Get the next bit of a transmitted serial bit stream.
175  \param user_data An opaque point which must point to a transmitter context.
176  \return the next bit, or PUTBIT_END_OF_DATA to indicate the data stream has ended. */
177 SPAN_DECLARE_NONSTD(int) async_tx_get_bit(void *user_data);
178 
179 /*! Initialise an asynchronous data receiver context.
180  \brief Initialise an asynchronous data receiver context.
181  \param s The receiver context.
182  \param data_bits The number of data bits.
183  \param parity_bits The type of parity.
184  \param stop_bits The number of stop bits.
185  \param use_v14 TRUE if V.14 rate adaption processing should be used.
186  \param put_byte The callback routine used to put the received data.
187  \param user_data An opaque pointer.
188  \return A pointer to the initialised context, or NULL if there was a problem. */
190  int data_bits,
191  int parity_bits,
192  int stop_bits,
193  int use_v14,
195  void *user_data);
196 
197 SPAN_DECLARE(int) async_rx_release(async_rx_state_t *s);
198 
199 SPAN_DECLARE(int) async_rx_free(async_rx_state_t *s);
200 
201 /*! Accept a bit from a received serial bit stream
202  \brief Accept a bit from a received serial bit stream
203  \param user_data An opaque point which must point to a receiver context.
204  \param bit The new bit. Some special values are supported for this field.
205  - SIG_STATUS_CARRIER_UP
206  - SIG_STATUS_CARRIER_DOWN
207  - SIG_STATUS_TRAINING_SUCCEEDED
208  - SIG_STATUS_TRAINING_FAILED
209  - SIG_STATUS_END_OF_DATA */
210 SPAN_DECLARE_NONSTD(void) async_rx_put_bit(void *user_data, int bit);
211 
212 #if defined(__cplusplus)
213 }
214 #endif
215 
216 #endif
217 /*- End of file ------------------------------------------------------------*/
Definition: async.h:133
SPAN_DECLARE_NONSTD(int) async_tx_get_bit(void *user_data)
Get the next bit of a transmitted serial bit stream.
void(* put_msg_func_t)(void *user_data, const uint8_t *msg, int len)
Definition: async.h:93
void * user_data
An opaque pointer passed when calling put_byte.
Definition: private/async.h:73
The link protocol (e.g. V.42) has disconnected.
Definition: async.h:87
Notification that a modem has detected signal quality degradation.
Definition: async.h:81
An abort signal (e.g. an HDLC abort) has been received.
Definition: async.h:73
const char * signal_status_to_str(int status)
Convert a signal status to a short text description.
Definition: async.c:42
Regular octet report for things like HDLC to the MTP standards.
Definition: async.h:79
Notification that a modem retrain has occurred.
Definition: async.h:83
The modem is training. This is an early indication that the signal seems to be of the right type...
Definition: async.h:63
int use_v14
TRUE if V.14 rate adaption processing should be performed.
Definition: private/async.h:69
int stop_bits
The number of stop bits per character.
Definition: private/async.h:67
The carrier signal is up. This merely indicates that carrier energy has been seen. It is not an indication that the carrier is either valid, or of the expected type.
Definition: async.h:58
async_tx_state_t * async_tx_init(async_tx_state_t *s, int data_bits, int parity_bits, int stop_bits, int use_v14, get_byte_func_t get_byte, void *user_data)
Initialise an asynchronous data transmit context.
Definition: async.c:208
An error has occurred in the link protocol (e.g. V.42).
Definition: async.h:89
void(* put_byte_func_t)(void *user_data, int byte)
Definition: async.h:99
void(* put_bit_func_t)(void *user_data, int bit)
Definition: async.h:105
A modem has completed its task, and shut down.
Definition: async.h:77
void(* modem_status_func_t)(void *user_data, int status)
Definition: async.h:114
int data_bits
The number of data bits per character.
Definition: private/async.h:63
int(* get_bit_func_t)(void *user_data)
Definition: async.h:108
The data stream has ended.
Definition: async.h:71
int(* get_msg_func_t)(void *user_data, uint8_t *msg, int max_len)
Definition: async.h:96
The link protocol (e.g. V.42) has connected.
Definition: async.h:85
Definition: private/async.h:60
The modem has trained, and is ready for data exchange.
Definition: async.h:65
put_byte_func_t put_byte
A pointer to the callback routine used to handle received characters.
Definition: private/async.h:71
Definition: private/async.h:34
A break signal (e.g. an async break) has been received.
Definition: async.h:75
Definition: async.h:135
The carrier signal has dropped.
Definition: async.h:54
Definition: async.h:137
Packet framing (e.g. HDLC framing) is OK.
Definition: async.h:69
async_rx_state_t * async_rx_init(async_rx_state_t *s, int data_bits, int parity_bits, int stop_bits, int use_v14, put_byte_func_t put_byte, void *user_data)
Initialise an asynchronous data receiver context.
Definition: async.c:83
int(* get_byte_func_t)(void *user_data)
Definition: async.h:102
The modem has failed to train.
Definition: async.h:67